In many applications of portable lighting products, users are ultimately concerned with such factors as bulk of product and the running life of that product. For example for flashlights with 6 or 8 dry cells in series, these may need to be replenished or replaced either at the start of a shift or during a shift and the human condition will dictate that it will be at the worst possible time.
Generally with 6 and 8 dry cell flashlights, the dry cells are connected in series in a straight line making the bodies of the flashlights relatively long. This can render such flashlights as menacing to the general public because of a club like appearance. Also their relatively long length renders them difficult to store in cupboards and vehicles, or when carried on belts they can interfere with the wearer's movement. Such flashlights can at times be any thing up to 1 meter or 39 inches long.
Also, in today's market, brighter operating lamps are being developed, but at the relatively high voltages of 9 or 12 volts, the filaments of such lamps are relatively fragile. Such fragility can b directly proportional to the voltage at which the lamp is operated.
Whilst a solution to the first and second mentioned difficulties can be to provide the power supply from sets of dry cells in parallel, this solution results in an additional problem. When sets of series connected dry cells are connected in parallel, there are risks of dissipation and transfer of energy from one set of dry cells to another, when they are not powering a lamp. This can lead to premature dissipation of the available energy in the dry cells. Potential risks of premature dissipation is one reason why manufacturers have not utilised parallel dry cell arrangements for dry cell powered products.
It is an object of the invention to provide a portable lighting product, a portable lighting product circuit and a method of functioning of a portable lighting product circuit which ameliorates, at least partially, at least one of the disadvantages of the prior art.
Whilst the following discussion and description of the embodiments relates in part to flashlights, it will be understood that the invention is applicable to any portable lighting product, and can be readily incorporated therein without departing from the scope of the following inventions.